Why should I NOT use Opera?

If you use GNOME or some window manager based on GTK+, it is needed to load additional libraries because Opera it's a Qt application.

Some webpages don't display correctly because they are not following the web standards (Opera sticks to standards).

Installation

To install the latest stable Opera:

# pacman -S opera

Note: this will install Qt4 shared build.Note 2: on x86_64, it will install Qt3.

Static build

Opera is also available statically linked against the Qt libraries, removing them as dependencies.
It is available for i686 as "opera-static" in the AUR.

Other options

Microsoft Fonts and Opera

If you have at the time of Opera package installation the package ttf-ms-fonts Opera will then use those fonts which may look unattractive.
To make Opera use by default Gnome fonts or whatever is default on your system remove the ttf-ms-fonts package and then install Opera.

Also note that all fonts are configurable at Tools -> Preferences -> Advanced -> Fonts

Optional tweaks

To remove the tray icon, launch Opera with the -notrayicon option.

To make the menus look nice, do

# pacman -S polymer

then run qtconfig (it will be located in /opt/qt/bin) and set the polymer theme for Qt applications.